Category: Claims handling · Reviewed by Amy Price, Account Executive · Last reviewed 2026-06-11
Quantum assessment is the process of estimating the value of a claim — the damages, losses and consequential costs the insured (or third party) is entitled to recover — by reference to the legal heads of loss, the available evidence and the relevant comparators.
Quantum is the value side of a claim, as distinct from liability (the question whether the claim should be paid at all). A defence handler must understand both. Quantum analysis runs in parallel with liability analysis throughout the life of the claim; the case-reserve is essentially the product of liability probability multiplied by expected quantum.
For first-party property and BI losses, quantum is the cost of restoring or replacing what was damaged plus the consequential financial loss. For third-party liability claims, quantum is the damages the claimant would be awarded by a court — general damages for non-financial loss and special damages for financial loss, plus interest and costs.
Quantum is governed by substantive law, the policy wording and the available evidence.
For personal injury, the principal source is the Judicial College Guidelines for the Assessment of General Damages in Personal Injury Cases (current edition), supplemented by the published case law on awards (typically reported in Kemp & Kemp on Personal Injury Law and Practice and Personal Injury Quantum).
For commercial damages, the foundational principle is restoration to the position the claimant would have been in but for the breach (Robinson v Harman (1848) 1 Exch 850; Livingstone v Rawyards Coal Co (1880) 5 App Cas 25). The leading modern authorities include Wellesley Partners LLP v Withers LLP [2015] EWCA Civ 1146 and the body of professional negligence cases applying it.
For property losses, the SAAMCO (South Australia Asset Management v York Montague [1996] UKHL 10) and Manchester Building Society v Grant Thornton UK LLP [2021] UKSC 20 line of authority sets out the scope-of-duty principle that limits recoverable damages to those within the scope of the duty owed.
For business interruption, the policy wording is critical; FCA v Arch [2021] UKSC 1 reshaped BI claims handling on the application of trigger, causation and aggregation to non-damage extensions.
Quantum assessment runs through a sequence:
First, identify the heads of loss available under the substantive law. For PI: general damages (PSLA, loss of amenity), past loss of earnings, future loss of earnings, care costs, treatment costs, accommodation costs, aids and equipment, miscellaneous. For commercial loss: direct loss, consequential loss, mitigation costs, costs of investigation.
Second, gather the evidence for each head. Medical reports, employment records, financial records, expert quantum reports, claimant’s own statements.
Third, value each head. General damages by reference to the JC Guidelines; special damages by reference to the actual evidence; future loss by reference to the Ogden Tables (PI multipliers) or expert projections (commercial loss).
Fourth, deduct any contributory negligence or other discounts. For PI, contributory negligence reductions are typically 20-50% depending on the facts. For commercial loss, betterment, taxation adjustments and mitigation discounts apply.
Fifth, add interest. For PI special damages, interest on past losses at half of judgment rates from accrual to assessment. For commercial loss, interest under the Senior Courts Act 1981 section 35A at a commercial rate.
Sixth, consolidate into a range. The quantum analysis usually produces a best, central and worst case (from the insurer’s perspective). Settlement negotiations and case reserves are set by reference to the central case, with sensitivity to the range.
For complex claims, quantum is run through expert input. A forensic accountant produces a damages report. A care expert produces a care costs projection. An employment expert produces a loss-of-earnings projection. Each is tested in conference and at JSM/mediation.
Quantum assessment is iterative. As liability theories develop, the scope of recoverable damages may change. SAAMCO in particular has produced enormous variations in quantum outcomes depending on the precise duty of care found.
“Schedule of loss” is the claimant’s formal quantum document; the defendant produces a “counter-schedule” responding to each head.
“Joint quantum statement” is sometimes used where the parties’ quantum experts can agree the underlying figures even if the legal heads remain in dispute.
“Provisional damages” awards (in PI) provide for further compensation if a defined deterioration occurs in the future. Used where the claimant’s medical prognosis is uncertain.
“Periodical payment orders” (PPOs) replace lump-sum future-loss damages with annual payments for the claimant’s life. Common in catastrophic injury cases.
“Loss of a chance” damages apply where the claimant has lost the opportunity of a benefit rather than the benefit itself (Allied Maples Group Ltd v Simmons & Simmons [1995] 1 WLR 1602).
A claimant in a commercial PI claim alleges that the defendant’s negligent valuation of a property caused a £2.4m loss on a development. Quantum analysis: the claimant’s primary case is that the development would have proceeded at the higher valuation and generated £2.4m of additional profit. The defence’s primary case is that, under the SAAMCO scope-of-duty principle (as refined in Manchester Building Society), the defendant is liable only for the difference between the actual valuation and a non-negligent valuation, capped at the foreseeable loss. The defendant’s quantum range: £680,000 to £1.1m. The claimant’s range: £2.0m to £2.4m. Negotiated settlement at JSM: £1.35m. The quantum gap was driven entirely by the SAAMCO analysis; the underlying property and development facts were largely agreed.
By Matt Bartlett, Director, on 2026-06-11. Next review: 2026-12-11.
This entry is part of the Apex Insurance Wiki. Last reviewed by Matt Bartlett on 2026-06-11. Apex Insurance Brokers Limited, FCA FRN 724952, Companies House 07014570. Not regulated advice — consult your broker on your specific position.
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